How does Smoking Affect the Cilia?

Karyn Maier
Karyn Maier

Cilia are tiny hair-like organelles that reside on the surface of cells. In the human body, many are found on cells where they sweep debris away from the lungs and nasal cavities. They also line the Eustachian tubes and sinuses, as well as the fallopian tubes in women. For each ciliated cell in the body, there are between 100 and 200 cilia, each one anchored by another organelle known as the basal body. Constructed of hollow cylindrical microtubules, each basal body is arranged in the same orientation to allow the movement of fluid and particles to occur in one direction.

Cilia lining the sinuses and bronchial tubes can be damaged or paralyzed by smoking.
Cilia lining the sinuses and bronchial tubes can be damaged or paralyzed by smoking.

There are two types of cilia: motile and non-motile. The former continuously move in a wave-like fashion in a single direction, while the latter function as sensory organs that respond to stimulus. All cilium, however, are composed of several types of proteins that work synergistically together to stimulate ciliary motion. If one protein is absent or becomes damaged, then the organelles may remain rigid. Polycystic kidney disease and tubal pregnancies, for example, are due to those that do not function correctly.

Damaged cilia often result in an unproductive cough.
Damaged cilia often result in an unproductive cough.

The most common reason to suffer damaged or paralyzed cilia, however, is smoking. Normally, healthy ones in the bronchial tubes work in sync with specialized cells that produce mucous to capture and remove impurities from the lungs. Smokers, on the other hand, are subjected to about 4,000 toxic chemicals in cigarette smoke, including arsenic, methane, and carbon monoxide. This damages the organelles, and dirt, environmental pollutants, and toxins from cigarette smoke remain in the lungs. Furthermore, these toxins migrate from the lungs via the bloodstream to other organs.

Smoking is the most common method of damaging the cilia.
Smoking is the most common method of damaging the cilia.

In response to the presence of excess irritants, mucous cells in the lungs become stimulated to produce more mucous than they normally would. Of course, with damaged cilia, the lungs have no means of moving the mucous out. This usually results in an unproductive cough. In fact, the damage caused by smoking leaves the smoker at significantly higher risk for frequent respiratory infections, or chronic bronchitis.

Smoking increases the risk of COPD.
Smoking increases the risk of COPD.

Continued smoking may eventually lead to chronic obstructive pulmonary disease (COPD, including chronic bronchitis and emphysema) or lung cancer. In fact, smoking eventually destroys the cilia, which may then be displaced by an excessive number of basal cells or squamous cells. Over time, these cells may become cancerous. They may also become rogue, escaping through lung tissue and invading other parts of the body.

Remarkably though, stopping smoking can undo the damage to cilia rather quickly. In fact, they begin to repair themselves and regenerate in number within only three days after quitting. It should be noted that coughing is a common side effect to this process and may last from a few days to several weeks. This is because the restored cilia are working overtime to remove impurities and mucous from the lungs. If cough persists for more than eight weeks, however, a medical professional should be consulted.

Smokers who quit can quickly reverse at least some damage to the cilia.
Smokers who quit can quickly reverse at least some damage to the cilia.
Karyn Maier
Karyn Maier

Contributing articles to wiseGEEK is just one of Karyn’s many professional endeavors. She is also a magazine writer and columnist, mainly for health-related publications, as well as the author of four books. Karyn lives in New York’s Catskill Mountain region and specializes in topics about green living and botanical medicine.

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Discussion Comments


I'm pretty sure once you have "killed" your cilia there is no way to make them functional again. Do you have sources for how quickly you claim that cilia damage can be reversed?


The tobacco companies put poisonous chemicals into cigarettes. Those chemicals are not in the marijuana plant. Yet you don’t usually filter marijuana as extensively as a cigarette; there are still burnt plant tars and carcinogens within both plants once smoked. Fortunately, if marijuana plants are grown ethically, then there shouldn't be too much to risk, cancer wise, since the human body can naturally absorb and rid itself of the burnt plant material that was ingested into your lungs. Smoke from anything on earth can paralyze the cilia and cause its functions to cease until the cilia and lungs have been given time to re-grow and work again. I have been a marijuana smoker for over six years now and my only concern is the fact that I can’t put on extreme amounts of muscle from training at the gym due to the oxygen deprivation of smoke. (need oxygen to build muscle). Running isn’t even much of an issue for me, thankfully.

Cilia can grow back after smoking for however long, but what matters is if cancer has already developed.


Cannabis broad leaves have more carcinogens than tobacco broad leaves, but cannabis bud has one-third less, so it's not actually true that cannabis is more dangerous to smoke than cigarettes. After all who smokes cannabis broad leaves!? Juice them perhaps but sure don't smoke them.


@anon266713: Someone was smoking in the cabin below you? You get worse damage by walking around in any city with traffic than you do from secondhand smoke.

Some people would not be happy unless the whole world was regulated and sculpted to fit their world view only, with no thought or care for anyone else's opinions or life choices.


I am 60 years old and quit smoking after 38 years. I had a heart workup that was normal, and my chest X-ray was normal. I had a cough and mucus for years before I quit. This stopped with quitting, but I have moderate shortness of breath with exertion. I had pulmonary function tests that were good, showing no emphysema. I did not develop cough or mucus after quitting which I expected, just shortness of breath. The doctor said I have chronic bronchitis, and to use albuterol. I do not understand how I can have chronic bronchitis with no cough or sputum?


Good news. After you quit smoking, the cilia grows back. But if you start smoking, the smoke will literally kill the cilia, and your lungs will turn blackish grey, because they will be full of dirt, dust and other dirty things. Please read "It Couldn't Just Happen" chapter 15. It will explain things a lot better. I hope this helped!


I have serious, violent reactions to both cigarette smoke and marijuana smoke. I try to just stay away from it and give no business to any place that would expose my health to such dangers.

However, recently I was trapped on a ship with a rude chain-smoker in the cabin below our suite or maybe forward, and it came into our suite for seven days. Needless to say we'll no longer go on NCL and will cruise on a more luxury line with zero tolerance smoking programs.

I try to never take drugs of any sort, and was forced after three weeks into antibiotic world. Now we have a doctor who knowingly gave me something I'm severely allergic to. It's in his chart. I told him. I had a high fever and couldn't focus (again, thank you, smoker). After just one tab, I had a vicious rash.

Bottom line, smoking is costly to even healthy people and I really resent paying $12,000 for a cruise and coming home deathly ill, then resent doctors who are sloppy. Changing both doctors and cruise lines.


O.K., it only takes a minute to find this to be false. Marijuana has significantly more of certain dangerous poisons than cigarette smoke. No, there's no nicotine, but that doesn't matter.

Ammonia levels were 20 to 30 times higher in the marijuana smoke than in the tobacco smoke, while hydrogen cyanide, nitric oxide and certain aromatic amines occurred at levels three to five times higher in the marijuana smoke. Smoke is smoke.


I'd say that smoking marijuana does not affect the cilia as bad as smoking cigs do. That's just my guess, since I recently quit smoking cigs but still smoke weed.

I still have that smoker's cough letting me know the cilia are doing their thing. It's not like smoking marijuana gets rid of that cough as if another cig would. This is just a guess though, basing off of my experience.


how would you cite this article?


For the people asking what causes it: we talked about it in my Biology class and I believe the professor said the nicotine was a cause for it, though I'm sure it's possible for other substances to contribute to it too.


Question: I have been a smoker for about ten years, both pot and cigarettes. I recently quit a few weeks ago because I could not seem to clear my throat of mucus. It is horrible when i eat. It feels like the food is getting stuck in my throat. Can paralyzed cilia make it hard to swallow your food?


So is this caused by just the smoke or what it is you're smoking?


In regards to the question about the effect of smoking pot on the cilia. From experience I can give an unequivocal yes to your question. Smoking pot damages the cilia. Never smoked cigarettes in my life. Never. But smoked pot moderately for 30 years. Ended up with the same sort of damage to my cilia as a cigarette smoker.


Does marijuana affect the cilia in such a dramatic manner as cigarettes?


does anyone know if nasal cilia can regenerate after quitting smoking. I've been smoking a pack to a pack and one half for twenty years.


What substances paralyze the cilia?


Does anyone know if the cilia in the fallopian tubes heal as quickly or at all as it does in the lungs?


Excellent article. May I ask your sources? Thank you in advance.

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